Speed Versus Weight
 

I don't remember where I heard this but i remember that a heavier bb will hurt more, sorry if that is a little vague but here is my question:

For example:
Using a .20 gram bb that shoots at 350 fps
Using a .25 gram bb that shoots at 270 fps

These are just guesses and I do not know exactly what the fps is.
So if you use a heavier bb but the fps is slower, would that hurt more than using a light bb but the fps being faster? I dont know if this is a stupid question but i just wanted to know.

Thanks,
Vince

energy = mass x velocity squared
momentum = mass x velocity

Energy is always the same, momentum can change. Heavier BB's have more momentum so can punch through brush better and it does have more of a thwack when they hit you. Don't know if it hurts more but I know their louder when they hit cloth. Heavier BB's are also less effected by wind.

From what I've seen, there is about 30-40fps lower with a 0.25g than a 0.20g. And a 100fps difference between a 0.20g and a 0.36g BB.

And yes, heavier yet slower hit harder.

From the muzzle, either BB weight will have the same energy, but over a larger distance, heavier BBs will carry more energy and thus, will hit harder.

It's an interesting question I've wanted to solve with empirical tests but never had the time. I've wanted to make fps measurements thru an optoelectronic chrony (ones with the wands) to take fps measurements at different ranges with different weight pellets with the same gun.

I would guess that at very close ranges, the mass of a pellet would not affect impact energy, but heavier pellets would carry higher impact energy at longer ranges.

Perhaps a more useful piece of data would be time to target. Heavier bbs start at a lower muzzle velocity, but carry their speed better. There may be a tradeoff point where one might choose a moderately heavy bb for a given muzzle energy and engagement distance.

http://www.jayandwanda.com/tt/ballspeed_calc1.html

It's what I use.

By varying the Time Interval, you can determine the distance traveled, and the final velocity. Takes into account air friction at any given elevation.

I remember seeing a graph someone made for this.

It compared the speed vs the distance between .2g and .25g pellets.

I remember prior to 90 ft, a .2g pellet is travelling faster, after 90 ft, the .25g pellet is travelling faster. The .25g pellet travelled furthur I think due to it's sustained fps after 90 ft, but I could have remembered wrong.

So if you're playing cqb and other smaller fields where 90 is the maximum distance you'll want to shoot, a .2g pellet will actually get there faster (well...at 90 ft they will get there together).

As for the pain factor, I haven't seen any difference in actual play unless you shoot someone at something less than 30 ft. Even then, it's not a terrible difference.


***Ah, I found it:http://www.arniesairsoft.co.uk/?filn..._dist_time.htm

If you read it, you see that at 50 ft, the two weights have the same velocity, but the .2 has travelled furthur. At 90 ft they travelled the same distance.

Now if you translate that into energy, like I said, anything over 30 ft, you're pain factor is almost the same.